BERLIN -- As-needed injections of ranibizumab (Lucentis) for diabetic macular edema (DME) appear to be safe in the long run, researchers said here.

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This study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

As-needed injections of ranibizumab (Lucentis) for diabetic macular edema appear to be safe for up to 3 years of treatment, a study has found.

Note that improvements in visual acuity were maintained for those who had ranibizumab injections during the first year of the trial.

BERLIN – As-needed injections of ranibizumab (Lucentis) for diabetic macular edema (DME) appear to be safe in the long run, researchers said here.

After a total of 3 years, there were no significant differences in ocular or non-ocular adverse events whether patients initially had injections of the drug or laser surgery, Gabriele Lang, MD, of the University Eye Hospital in Ulm, Germany, and colleagues reported at the European Association for the Study of Diabetes meeting here.

The findings come from a 2-year, open-label, extension study that followed the year-long, randomized, controlled RESTORE trial.

Improvements seen at 12 months "were maintained during the 24-month extension study in patients initially treated with ranibizumab, and improved in patients initially treated with laser in the core study and subsequently treated with ranibizumab in the extension study," Lang said during the oral presentation.

Ranibizumab was approved for use in DME in the U.S. in August. It had previously been approved for wet age-related macular degeneration (AMD), though many clinicians have been using off-label another vascular endothelial growth factor (VEGF) inhibitor, bevacizumab (Avastin), for both AMD and DME, because it carries a cheaper generic price tag.

Both drugs are effectively marketed in the U.S. by Roche, since ranibizumab maker Genentech is one of its subsidiaries. In Europe, Novartis markets ranibizumab.

Currently, the standard treatment for DME is laser photocoagulation of the retina. The first part of the phase III RESTORE trial was conducted to see how 0.5-mg injections of ranibizumab taken as-needed would compare, and it ultimately bested laser therapy in terms of improvements in visual acuity.

So the researchers conducted a 2-year, open-label, extension phase of the trial to assess long-term safety and efficacy, with a primary endpoint of the incidence of ocular and non-ocular adverse events.

In first phase, patients had been randomized to one of three groups: ranubizumab alone (with a sham laser procedure), ranibizumab plus a real laser procedure, or laser therapy alone (plus sham injections).

For the second part, all patients were put on as-needed ranibizumab. Of the 240 who entered this phase, 181 had completed all 3 years of the study.

The mean number of injections during the 2-year extension phase fell between 6 and 7 for all three groups, and that number had declined over the course of the study, with most patients only needing 2 to 3 injections in the final year of the study.

Lang noted about 19% to 25% of patients across all treatment groups didn't need any ranibizumab injections during the 2-year extension phase.

Overall, she and colleagues found no significant differences in ocular or non-ocular events across groups during that time.

Between 50% and 60% of patients across groups had any ocular event -- chiefly eye pain and cataract -- and about 73% in each group experienced a non-ocular event, mainly nasopharyngitis, they reported.

Also, there were no cases of endophthalmitis, retinal tear, or retinal detachment over the 3 years of the study.

Improvements in visual acuity were maintained for those who had ranibizumab injections during the first year of the trial, and those who had only had laser surgery had significant gains in the follow-up phase, the researchers reported.

Mean best-corrected visual acuity was highest at 3 years with ranibizumab alone, with a gain of about 8 letters.

The group that had both injections and surgery held constant at 6.7 letters and surgery-only patients rose from a gain of 2.3 letters at one year to 6 letters by the end of 3 years.

Central retinal thickness values also merged at 3 years when all patients were taking ranibizumab, Lang and colleagues reported.

And those in either ranibizumab group from the start maintained their gains in NEI VFQ-25 composite and general vision scores, while those who had only had laser therapy improved their scores in the extension phase.

They concluded that the findings suggest the safety of ranibizumab use over 3 years given "no new ocular or non-ocular safety findings or increased safety concerns."